|
|
|
|
 |
 |
|
What is the blue/red up arrow located next to the FAQ's answer? |
|
|
This small two-color rollover icon will return your browser to the Frequently Asked Questions, Table of Contents page. This dynamic link allows you to return to the TOC look for other information relevant to your query.
|
|
|
|
|
|
|
What does, "RedHat Automated System Updates through RHN" mean? |
|
|
The Red Hat Network (RHN) delivers unrivaled control and management of Red Hat Linux-based systems. Red Hat Network automates software delivery with the latest updates to keep your systems secure, efficient and reliable.
CybrHost subscribes to the Red Hat Network Enterprise Service
Red Hat Network Enterprise Service includes all of the features of Basic Service, as well as features designed to simplify the management of large groups of systems:
System grouping:
Web servers, database servers, workstations and other workload-focused systems may be grouped so that each set can be administered in common ways.
Multiple administrators:
Administrators may be given rights to particular system groups, easing the burden of system management over very large organizations.
System Set Manager:
Actions may be applied to sets of systems instead of single systems. Work with members of a predefined system group, or work with an ad-hoc collection of systems. Install a single package to each, subscribe them all to a new channel, or apply all errata to them with a single action.
Package Profile Comparison:
Compare the package set on a system with the package sets of similar systems.
Massive Scalability:
Figuring out a list of outdated packages for a thousand systems would take days for a dedicated sysadmin. Red Hat Network Enterprise Service can do it for you in seconds.
The following advanced options are available to Enterprise Service:
Proxy Server:
Red Hat Network Proxy Server is a custom-built proxy system deployed on a customer's site that caches packages for distribution across a local Intranet while maintaining a single, secure connection to RHN. Customers who deploy the Proxy Server may also maintain their own customized channels.
Satellite Server:
Red Hat Network Satellite Server is a custom-built system which enables large organizations to store system profiles locally. The RHN Web interface is served from a local web server and is disconnected from the public internet; all package/errata management is done locally. The customer has complete discretion in maintaining a connection with RHN for updates to the official Red Hat Linux packages and channel package updates. RHN Satellite can work in tandem with RHN Proxy Server.
|
|
|
|
|
|
Can you provide an overview of the DNS system? |
|
|
The Root Nameserver System
The Root Nameserver System is comprised of three major components, the DNS protocol itself, the root zone file and the root name servers.
The DNS protocol only uses relative time, that is, periods of time relative to an arbitrary starting point, for the purposes of timers to insure proper timeout and retry periods. As such, there is no dependence on absolute time, e.g., calendar dates.
The root of the Internet namespace consists of a single file, the root zone file, which describes the delegations of the top level domains and the associated records necessitated by the DNS protocol to implement those delegations. Currently, this file is maintained by Network Solutions Incorporated of Herndon, Virginia, USA and is made available to the 12 secondary servers from the primary a.root-server.net. Change control of this file is held by the IANA with changes, typically modifications of the name servers for top level domains, being made approximately once or twice a week.
The root zone file is made available to the root name servers either in-band via the DNS protocol itself (through zone transfers as described in RFC 1034) or out-of-band via the FTP protocol (as described in RFC 952). Given the relatively small size of the root zone, most updates of the root zone file are propagated via zone transfers.
The root zone file itself is composed of 7-bit ASCII characters and contains an SOA record, NS records for each of the top level domain zone delegations, and associated glue records. As a (human) administrative convenience, the SOA serial number is often represented as a date indicating the last modification to the zone file, typically of the form YYYYMMDDXX where YYYY is the year, MM is the month (1-12), DD is the day (1-31), and XX is a sequence number indicating the number of updates within a day.
The root name servers are the machines that provide access to the root zone file for proper DNS protocol operation. Due to protocol limitations, the number of these machines is currently limited to 13, although efforts are underway to remove this limitation. A conscious effort has been made to diversify the administration of these 13 machines in several areas. As of this writing, the root name servers are operated by the US military, commercial organizations, non-profit organization, Internet service providers, universities, and research institutes with 3 of the 13 servers being operated outside the US, one in London (administered from the Netherlands), one in Japan, and one in Sweden.
All of the 13 servers have some "hardening" with respect to environmental contingencies. This hardening includes the use of controlled physical access, protection against power grid and cooling failures with UPS protected power with local generator capacity for extended outages, and diverse Internet connectivity in layers 1 through 3. The root servers themselves all use some variant of the Unix operating system, however both the hardware base and the vendors' Unix variants are relatively diverse: of the 13 root servers, there are 7 different hardware platforms running 8 different operating system versions from 5 different vendors.
|
|
|
|
|
|
|
How do I change the time zone on CybrHost servers? |
|
|
Short Answer
You can't change the server time.
Long Answer
CybrHost sets the basic time of all of its' servers to Coordinated Universal Time (UTC) which is the international time standard. It is the current term for what was commonly referred to as Greenwich Meridian Time (GMT). Zero (0) hours UTC is midnight in Greenwich England, which lies on the zero longitudinal meridian. Universal time is based on a 24 hour clock, therefore, afternoon hours such as 4 pm UTC are expressed as 16:00 UTC (sixteen hours, zero minutes).
Since a day is 24 hours long, the world may be split into 15 degree wide longitudinal bands (360 degrees/24 hours). Each band represents one hour. As an example, Huntsville Alabama is located at approximately 90 degrees west longitude, hence, local time lags UTC time by 6 hours (90/15, assuming Central Standard Time, 5 hours in Central Daylight Time). So, if the universal time is 14:30 UTC, United States Central Standard Time would be 8:30 am CST.
This time can only be changed by our Network Operations staff. We receive this request quite often due to the fact that Miva Merchant has no capabilities to dynamically change the internal time. CybrHost has previously requested this feature to be added to Merchant to no avail. Our requests seem to have fallen of deaf ears.
Fortunately, Merchant is open source so any third-party vendor could add this feature if desired. If you have the need to report times other than UT, we recommend that you purchase a third-party module called HTML Formatted Merchant Notification by TRUXOFT.
|
|
|
|
|
|
CYBRHOST
